Spyderco Calypso Jr with ZDP-189 review request

[klattman]

Cliff - I got my hands on a Starrett caliper, and measured the thickness at the edge bevel/primary grind shoulder of a number of my knives. The results, in inches, are:

Queen stockman, spey blade 0.012
Eye Brand moose stockman, main blade 0.012
Opinel #8 stainless 0.013
mini Ritter RSK 0.015
Buck Cabelas Alaskan Guide Crosslock 0.015
Victorinox Soldier 0.015
Kissing Crane large whittler, main blade 0.015
Buck Mayo 0.022
D2 mini-Grip 0.022
Calypso Jr, black FRN 0.025
S30V Native 0.030

All were measured the same way, and should give a good relative scale of some of my knives. These are all pretty much as they came from the factory, I have not changed the grind appreciably on any of them. The Mayo cuts better than the edge bevel thickness would indicate because of the deep hollow grind, and the Crosslock cuts like nobody's business. Note how much thicker the Calypso Jr and Native edge bevels are.

For what it's worth, the pictures that Vassili posted of his ZDP-189 Calypso Jr show a significantly finer edge bevel than my Calypso Jr has.

In case you haven't noticed, I have a thing about edge bevel thickness in small utility blades. I have convexed a number of my blades.

Interesting results. I have already significantly sharpened my gray calypso, so I'm not sure if it really is that different from the ZDP version.

My measurements could be off. My micrometer is not one of the best...

 

[klattman]

FWIW, I've been cutting a lot of cardboard and wood, and it still shaves arm hair above the skin. The only other production knife that I've had do this is a straight razor! I have steeled it once, and it came right back to NIB sharpness.

Sounds good. A good head-to-head test would be to use a NIB gray VG10 calypso and a NIB ZDP version. First we'd have to check that they have the same geometry. If they do, then alternate cuts through sheets of cardboard. Keep going until each blade tears rather than cuts and provide total number of inches cut for each blade. See if there is any chipping on either. This would give us a pretty good idea how the new ZDP performs.

Problem is it may take a lot of effort to get there.

 

[Cliff Stamp]

...I have a thing about edge bevel thickness in small utility blades.

I do for all blades, it should be the minimal amount for necessary durability. Thanks for the information, I was curious about the Ritter, do you know if that is the spec'ed geometry or possibly a deeper grind?

Considering amount of cardboard, it won't take much, even one normal box has about 100 m if cut into thin strips. If you do this fast on a small section of blade, it will induce blunting readily.

It won't take much more than 5-10 minutes to wear the blades down to 5-10% of optimal sharpness. The time comes into sharpening them and repeating it 3-4 times to check for consistency.

-Cliff

 

[klattman]

I do for all blades, it should be the minimal amount for necessary durability. Thanks for the information, I was curious about the Ritter, do you know if that is the spec'ed geometry or possibly a deeper grind?

Considering amount of cardboard, it won't take much, even one normal box has about 100 m if cut into thin strips. If you do this fast on a small section of blade, it will induce blunting readily.

It won't take much more than 5-10 minutes to wear the blades down to 5-10% of optimal sharpness. The time comes into sharpening them and repeating it 3-4 times to check for consistency.

-Cliff

That's a good point, I guess one could shave less than a cm at a time and the box would last a while. It would certainly be revealing.

The other trick is in comparing two knives with identical grinds and sharpenings. Two NIB Calypso's one in VG10 and one ZDP would be a good test. If you only test with one knife, is the result (good or bad) due to the steel or the way it's shaped/sharpened, etc.

I may get around to trying to sharpen my old VG10 caly and the ZDP the same, and giving this a shot...

BTW, Cliff, didn't you get one of these to play with yet?

 

[Cliff Stamp]

That's a good point, I guess one could shave less than a cm at a time and the box would last a while.

You can get about a mm easily with a little practice. I cut them so close they curl up like wood shavings.

...didn't you get one of these to play with yet?

Probably in the mail, it might get here in a month or so. One of the benefit of living in the sticks.

-Cliff

 

[lambertiana]

Cliff - my mini Ritter RSK is the factory edge, I received it less than a week ago. My brother came out for a backpacking trip and I saw his and had to get one. Mine appears to be about the same as his, so both of the mini-Ritters that I have seen have had very good geometry.

Now that I am seeing more pictures of actual production models, it looks like the ZDP-189 Calypso might have a decent edge bevel on it. This will be hard to resist....

 

[sodak]

Well, it's too late to check NIB sharpness, I've got it sufficiently blunted down now to assure my self that:

1. It's an extremely good steel at edge holding.
2. It's not magical, it does actually blunt. After a long while.

I went at it pretty hard today with the cardboard, so I don't know if the edge dulled from wear or if I drew the temper out with the speed of cutting.... It got very hot. I've been going at the wood pretty hard also, and I see no chipping at all, but haven't put it under the microscope yet.

In a while when I have some time, I will take one of my VG 10 Caly's and one of my ZDP 189 Caly's and profile them identically on my Edgepro. Then it should be fun to begin testing.